Braising

Cooking in a small quantity of liquid in a closed vessel, at a temperature below boiling. The food sits partly above the liquid, so it cooks in saturated air as much as in water. The purpose is usually collagen: it converts to gelatin slowly from 70 degrees C and much faster above 80 degrees C, and the closed vessel stops the meat drying while that happens. The sealed vessel also keeps the surface wet, so braised meat cannot brown until the lid comes off.